1. Field of the Invention
The present invention relates to a pixel structure, and more particularly to a pixel structure of a liquid crystal display.
2. Description of Related Art
Because of the high picture quality, high spatial utilization, low power consumption, radiation-free operation of thin film transistor liquid crystal display (TFT-LCD), it has become one of the mainstream displays in the market. At present, some of the basic demands on the liquid crystal display include properties such as a high contrast ratio, rapid response and wide viewing angle. The technologies capable of providing a wide viewing angle include, for example, multi-domain vertical alignment (MVA), multi-domain horizontal alignment (MHA), twisted nematic plus wide viewing film (TN+film) and in-plane switching (IPS).
Although a thin film transistor liquid crystal display with multi-domain vertical alignment can achieve the purpose of having a wide viewing angle, the presence of color washout problem is a major drawback. The so-called color washout refers to a viewer seeing different color scale adjustments of the image when the viewer views an image on a display at different angles. For example, the viewer may see a white-bias image when viewed at a more inclined angle.
At present, some methods for resolving the color washout problem have been proposed, including using a retardation film, reducing the cell gap or forming two different liquid crystal capacitors inside a single pixel structure. However, the effect produced by using a retardation film is quite limited, and reducing the cell gap would lower the yield and brightness. On the other hand, the method of forming two different liquid crystal capacitors of a single pixel structure requires the formation of an additional dielectric layer, which may cause mura and residual image problems.